The present invention relates to a method and apparatus for testing an integrated electronic device.
Micropatterning techniques have been quickly developed along with recent advances in electronic technology. In association with the development of micropatterning techniques, tests for integrated electronic devices have been an important factor for providing high-performance, low-cost devices.
Tests for finished electronic devices and tests during the fabrication process for electronic devices are very important for measuring electronic characteristics of integrated electronic devices. Devices that have poor test results are subjected to appropriate corrections in order to increase the yield of good devices and hence decrease the fabrication cost.
In order to test semi-finished electronic devices during the manufacturing process, probes of a specific test device for testing a specific process are directly brought into contact with predetermined positions of each electronic device to measure electronic characteristics thereof. This method is effective when electronic devices have a large circuit pattern and a low integration density. However, a minimum size for such probes is limited, and this conventional testing method is not suitable for electronic devices fabricated in a sub-micron process.
Another conventional electronic device electrical characteristic measuring apparatus of this type is exemplified by an electron beam tester with a potential measuring apparatus incorporated in a conventional scanning electron microscope. A predetermined driver is mechanically connected to an input side of each electronic device, and a measuring position is irradiated with a pulse beam pulsated in response to basic clocks supplied from the driver. A voltage contrast image of the electronic device is obtained on the basis of the magnitude of a secondary electron signal detected by the irradiated position.
Since the electronic device receives the basic clocks from its input side to form the voltage contrast image upon actual operation thereof, the device must be a finished product. Therefore, this conventional tester is not suitable for measuring electrical characteristics of electronic devices during their fabrication process. This technique is described in "VLSI TESTING USING ELECTRON PROBE", Scanning Electron Microscopy, Vol. 1.1, (1979), P. 285.